The subject of the present invention is a connection device for an electronic box.
Electronic boxes used in the industrial field are generally mounted in cabinets and are juxtaposed on one and the same rack, it being possible for several racks to be superimposed. These boxes possess a parallelepipedal general shape and each has one or more connection pins for connecting them to conducting cables that are connected to various types of equipment, such as timepiece systems, relays or signal processing equipment.
The connection pins connected to the electronic card contained in each electronic box are flat pins oriented parallel to the longitudinal assembling face of the box.
Since in general a box is accessible only via a longitudinal face, connection to the conducting cables is accomplished by means of connection modules each fixed to the longitudinal assembling face of a box. A connection module contains connection pieces, for connection to the horizontal flat pins, and a device for fastening the conducting cables which are brought into contact with the aforementioned connection pieces. The conducting cables are generally introduced into the connection module either via the top face thereof or via a longitudinal face thereof.
A connection module is fastened to the longitudinal assembling face of a box by an irreversible snap-fastening device, the module being brought up to the box by a movement transverse to this face. Should it be necessary to carry out work in a box, for example in order to change an electronic card, the connections between the conducting cables and the connection module have to be disconnected. After carrying out work in the box, the conducting cables have to be reconnected. From the foregoing, it follows that this operation is a lengthy and expensive operation, with the risk of wiring errors.
The object of the invention is to provide a connection device for an electronic box, comprising a connection module that can be wired before it is fitted onto the box and which can be disconnected from the box simply and quickly, without any deterioration and without requiring to disconnect the conducting cables. The object of the invention is therefore to provide a device in which a connection module can be disconnected and reconnected instantly, without disconnecting the conducting cables.
For this purpose, such a device, of the type comprising a connection module intended to be mated with the longitudinal assembling face of a box and making an electrical connection with, on the one hand, pins projecting from this longitudinal assembling face and, on the other hand, with conducting cables, is one in which:
the connection pins projecting from the longitudinal assembling face of the box are flat pins oriented so as to be parallel to the lateral faces of the box that are adjacent to neighboring boxes;
the longitudinal assembling face of the box is bounded laterally by two parallel recesses partly blocked near the longitudinal assembling face by at least one lug;
the assembling face of the module for joining onto the box includes slots oriented parallel to the lateral faces, each slot designed to receive a flat pin on the box, with the possibility of being moved along the direction of the slots of the module relative to the box as far as a locking position in which each flat pin is engaged in a tuning-fork-shaped connection piece placed in the module;
the assembling face of the module for joining onto the box is bounded laterally, over part of its height, by two parallel side walls each protruding forward and including an inward return having at least one recess, allowing, in a defined longitudinal position, passage for the lugs on the box and then the retention of said lugs in another longitudinal position corresponding to the locking position;
the assembling faces of the box and module respectively include, near their edge facing away from that for connection of the pins, a recess and a retractable resilient tab respectively, said tab being designed to fit into the recess in the locked position of the module.
From a practical standpoint, a connection module may be preequipped with conducting cables. To connect it to the electronic box, the module has to be moved transversely up to the box, the module being offset longitudinally with respect to the box, so that the lugs and returns on the box and the module respectively can interpenetrate. During this movement, the vertical pins on the box penetrate the slots in the module, the slots being placed in such a way that there is no electrical contact during this stage of the movement. When the opposing faces of the box and the module are in contact with each other, the operator moves the module longitudinally, so as to make electrical contact and then to effect the locking, which is obtained by engagement of the deformable tab belonging to the module in the recess provided in the longitudinal assembling face of the box. Retention of the module in the box is achieved by co-operation between the lugs on the box and the returns on the module, whereas the locking is achieved by co-operation between the tab on the module and the corresponding recess in the box.
By acting on this resilient tab, in the direction of extraction from the recess in which it is housed, it is possible, by a longitudinal movement followed by a transverse movement, to disconnect the module from the box. This disconnection is performed instantly and allows access to the inside of the box. It is worth pointing out that this disconnection is effected without disconnecting the conducting cables from the module. Work in a box can therefore be carried out simply and very quickly since any subsequent wiring operations are avoided, it being possible for the module, which has been disconnected together with the cables that are connected to it from the box, to be immediately reconnected to the box after the work has been carried out in the box or after the latter has been replaced.
To make the work by the operator easier, the respective lengths of the lugs on the box and of the recesses of the returns on the module are determined in order to form polarizers and to allow the module to be mounted on the box in only one way.
To make it easier to disconnect the connection module, the latter includes, in its face adjacent to its assembling face for joining onto the box, a recess giving access to the resilient locking tab in order to actuate the latter using a tool.
According to one advantageous embodiment of this device, a connection module comprises a body inside which are mounted a number of drawers, each containing a piece for connection to a flat pin on the box and at least one piece for fastening a conducting cable.
Each drawer is in the form of a piece having a parallelepipedal general shape, made of synthetic material, one of the lateral faces of which is open and the inside of which contains partitions projecting from the opposed lateral face, serving to press against, and to hold in place, the tuning-fork-shaped connection piece and the piece or pieces for fastening the conducting cables.
Several drawers are therefore juxtaposed inside the body of a module, the open face of each drawer being adjacent to the closed face of the neighboring drawer.
To fasten each drawer in the body of the module, the drawer includes, on its two faces adjacent to the open face, two snap-fastening spurs intended to penetrate two recesses provided in the facing walls of the module.
According to one embodiment of this device, the piece for electrical connection to a conducting cable is formed by a looped metal hairpin fitted over a stud on the drawer and projecting from that face of the latter on the opposite side from the open face.
Advantageously, and if it should be necessary to make an electrical connection between a piece and two conducting cables, the hairpin, for the retention of at least one cable, is a double hairpin obtained on the same metal strip slit along its length except in a joining region, the two parts, lying on either side of the slit, each having an opening for passage of a cable and each hairpin part being able to be actuated independently of the other part in order to fasten a cable. This solution makes it possible to use only a single element forming two hairpins, instead of two hairpins in the conventional case, this being advantageous from the economic standpoint and simplifying the fitting conditions.